Apparatus for evaluating range-table functions of two independent variables



0. GAEDKE APPARATUS FOR EVALUATING RANGE TABLE FUNCTIONS OF TWO INDEPENDENT VARIABLES bri'ginal Filed Jan. 29. 1929 x Wm Jtt'orn gs.

Patented Jan. 13, 1931 UNITED STATES PATENT OFFICE,

OTTO GAEDKE, OF HENG-ELO, NETHERLANDS, ASSIGNOR TO SIEMENS & HALSKE,

AKTIENGESELLSCI-IAFT, OF SIEMENSSTADT, NEAR BERLIN, GERMANY, A CORPORA- TION OF GERMANY APPARATUS FOR EVALUATING RANGE-TABLE FUNCTIONS OF TWO INDEPENDENT VARIABLES Original application filed January 29, 1929, Serial No. 335,947, and in Germany December 22, 1927. Divided and this application filed December 20, 1929. Serial No. 415,459.

My present application is a division of my application filed in the United States Patent Office on January 29th, 1929, Serial No. 335,947.

The invention relates to improvements in apparatus for evaluating range-table functions of two independent variables.

As such range-table functions come into consideration mainly the time of flight of the projectile, the timing of the fuze of the projectile and the elevation of the gun, but also the twist of the gun, the density of the air and the wind, which result when firing at targets located outside the horizontal plane, such as air targets. The two variables are the distance e and the height h of the target, i. e., its vertical distance from the horizontal plane.

Although it is possible to determine these values by the aid of the range-table, this procedure involves a great loss of time, and is rather complicated and liable to lead to reading errors.

It has therefore been attempted to determine these functions automatically by mechanical means and a kind of relief reproduction has, for instance, been employed for this purpose. This presents, however, considerable difiiculties in production and is very inaccurate, if it is not desired to employ inconveniently large dimensions. It is also known to effect the evaluation of such functions by graphical means, but this method requires much time, which is as a rule not available for gunnery purposes and particularly not when firing at air targets.

The object of the invention is to avoid the drawbacks of the known apparatus. It is based upon the fact ascertained by numerous investigations of range-tables and study of firing results, that the functions in question may be represented mathematically as the sum of two factors, of which the first represents a function of the one variable for the value 0 of the other variable, while the second factor of this sum forms the product of two functions of one of each of the two variables. The timing 2. of the fuze of the projectile may thus, for instances, be represented as follows the aid of comparatively simple cam drives operating with great accuracy.

According to the invention two curve drives are employed one of which is shaped according to a function of the one variable for the value 0 of the second variable, while the second curve drive determines the product of a function of the first variable and a function of the second variable.

In the drawings afiixed hereto and forming part of the specification two embodiments of the invention are illustrated by Way of example.

In the drawings Fig, 1 is a graph for explaining a construction of the invention, and

Fig. 2 is an embodiment of the invention constructed according to Fig. 1.

In Fig. 1 is shown a graph serving to explain a simplified embodiment of the invention. As an example is assumed the determination of the elevation of the gun as function of two variables. The distance values are then plotted as abscissae and angle values as ordinates.

A straight line 28 is then drawn through zero, along which are marked the individual heights. These are the points 29, 30 and so on. From the end point of the distance division, which in this illustration, for instance, is marked with the numeral 100 straight lines are dr. wn to the oints 29, 30 and so on indicating hei hts. 'nto the triangles thus formed are then traced the difference curves, which represent the difference between the elevation according to the range-table for the individual heights di minished by the elevation of the gun for the height 0 at the respective distance. These curves are designated by the reference numerals 31, 32 and so on. Now the amount of correction for the elevation of the gun is taken into account for the individual distances, which results from the individual triangles, and then the difference is taken into account between the triangle and the respective curve, for instance the difference between the triangle 0, 29, 100 and the curve 31. This has the advantage that the coarse correction derived from the triangles can be formed in a comparatively simple manner, and that the difference between triangle and curve as remaining fine amount,'is always comparatively small, and can easily be obtained with great accuracy by small curve gears.

In Fig. 2 of the drawing is illustrated an embodiment of the invention based on the diagram in Fig. 1. This consistsin general of three motion translating mechanisms, that is, mechanisms which will produce from a uniform motion or from the combination of two motions a variable motion. The distance value is transmitted to a first motion translating mechanism which includes a member 35 provided with a curved groove through a spindle 33 and bevel wheels 34. This curve member represents in accordance with Fig. 2 the elevation of the gun as function of the distance for the height 0 of the object. In this way a pin 36 and rack 37 are correspondingly moved and this motion is transmitted to a planet gear 39 across a spur and bevel gear 38.

The adjustment of the spindle 33 is also across bevel wheels 40 transmitted to a second motion translatin mechanism which includes a screw threaded spindle 41, upon which a slide 42 is adapted to move axially.

At right angles to the direction of motion of the slide 42 there is located a sliding rack 43. One end of the rack is pivotally con nected with a slotted lever 44. The lever 44 is adapted to swing around the point 45. A block 47 adapted to slide along the spindle 48 engages this slot 46. The screw spindle 48 is journaled in stationary bearings and is adjusted according to the height of the object fired at by means of bevel wheels 49 and the spindle 50. By the adjustments of the second motion translating mechanism above described a coarse correction is first effected of the amount of motion, determined by the cylinder 35 provided with the curved groove. A comparison of Fig. 2 with Fig. 1 shows that the spindle 48 corresponds with the straight line 28 of Fig. 1, while the axis of the abscissae in Fig. 1 corresponds with the screw spindle 41 of Fig. 2. The mechanism of Fig. 2 containing these two parts 41 and 48 thus supplies an amount of correction, which corresponds with the vertical lines dropped from the straight line 28, Fig. 1 on the axis of the abscissae. This amount is transferred to the planet gear by a pinion 51 in engagement with the rack 43, a spindle 52 and bevel wheels 53. It is now still necessary to effect a fine correction, which accounts for the difference of the straight lines 100, 29, 100, 30 and so on of Fig. 1 in relation to the curves 31, 32 and so on. For this purpose there is provided a third motion translating mechanism 54 in Fig. 2. This contains a camoid 55 having its surface formed according to the difference men tioned, which is rotated by the shaft 33 across the bevel wheels 56 in accordance with the distance value. On the surface of the camoid 55 is adapted to slide one end of a rack 57, which is adapted to move longitudinally upon a slide 58. The slide 58 rides upon a screw threaded spindle 59, which by means of the bevel wheels 60 and 61 is adjusted according to the vertical distance of the target from the horizontal plane. The slide 58 with the rack 57 is in accordance therewith displaced when the screw spindle 59 is turned. Since, as above described, the rack 57 contacts at one end with the curve member 55 it slides at right angles to the direction of adjustment of the slide 58 when this slide is adjusted. Since the motion translating mechanism produces a curve 32, it is hereinafter termed a curvilinear motion translating mechanism. The adjustment of the rack of the third motion translating mechanism is across a pinion 62 transmitted to a spindle 63, which in its turn adjusts a planet gear 64, which is connected with the planet gear 39 by the spindle 65. The spindle 66 adjusted from the planet gear 64 then gives the desired evaluation of the functions, in the example chosen.

The timing of the fuze and the time of flight of the projectile as functions of the distance and the height of the target may be evaluated in a corresponding manner. Instead of distance and height trigonometrical functions of the angle may be introduced unde which the target appears, in the case of airplanes the angle with the ground plane, as already mentioned before. If it is desired to determine the timing of the fuse by the aid of the new curve gear difference curves result in Fig. 2, which are located on the other side of the straight line appertaining thereto. In such a case the curve 31, for instance, would be located substantially below the respective straight line 100, 29. Otherwise the determination of these functions takes place in a corresponding manner, as described hereinbefore with the reference to the elevation of the gun. It will be understood, that instead of the grooved cylinders illustrated in the examples other gears of equivalent function may be employed, such as spiral wheel gears.

Various modifications and changes may be made without departing from the spirit and the scope of the invention, and I desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art.

I claim:

1. In apparatus for evaluating range-table functions of two independent variables, a spindle, a motion translating mechanism including a member grooved according to a function of the one variable for the value 0 of the second variable operating on said spindle, a second motion translating mechanism adapted to adjust said spindle additionally in accordance with the product of a function of the first variable and a function of the second variable including a slotted link gear adapted to supply a coarse correction and to copy the values of the product as approximate ordinates of a range table curve, and a further curvilinear motion translating mechanism adapted to supply a fine correction which last mechanism corrects the approximation to obtain the ordinate of the range table curve resulting for certain values of the second variable.

2. Apparatus for evaluating range table functions which depend upon the distance and height of the target, comprising a spindle, a body having a curved groove therein corresponding to a function of the distance for the value 0 of the height and adapted to adjust said spindle, and a motion translating mechanism adapted to adjust said spindle additionally in accordance with the product of a function of the distance and a function of the height, said motion translating mechanism comprising a slotted link gear adapted to give a coarse estimate of said product, and a curvilinear motiontranslating mechanism adapted to give an exact correction for said product to compensate for variations in the functions with the distance and height.

3. Apparatus for evaluating range table functions of two independent variables, com prising a spindle, a body having a curved groove therein corresponding to a function of one of said variables, and adapted to adjust said spindle, a pair of screw shafts having their axes at an acute angle to one another, a nut on each of said shafts adapted to be moved by rotation thereof, a member adapted to partake of the combined movement of said nuts and connected to said spindle to transmit its movement thereto, one of said screw shafts being adapted to be moved with said body, a member having a plurality of curved surfaces representing functions of said variables and adapted to be turned with said body having a curved groove, a screwshaft adapted to be rotated in accordance with a second variable and having a nut thereon, a member partaking of the movement of said nut and of said curved surfaces, and means for transmitting the movement of said member to said spindle.

4. Apparatus for evaluating range table functions of two independent variables, comprising a spindle, a motion translating mechanism including a member grooved according to a function of the one variable for the value 0 of the second variable operating on said spindle, and means adapted to adjust said spindle additionally in accordance with the product of a function of the first variable and a function of the second variable, these means comprising a second motion translating mechanism adapted to supply a coarse correction and to copy the values of the product as approximate ordinates of a curve, and a third curvilinear motion translating mechanism adapted to supply a fine correction which last motion translating mechanism corrects the approximation to obtain the ordinate of the range table curve resulting for certain values of the second variable.

In testimony whereof I affix my signature.

OTTO GAEDKE. 

